Determinación de residuos de fipronil en miel y polen por cromatografía de gases

This work describes the development of the analytical methodology for determining fipronil residues in honey and pollen samples by gas chromatography with two detecting systems: electron-capture detection (GC-ECD) and mass spectrometry (GC-MS). Fipronil was extracted from honey samples by solid-phase extraction, using alumina as adsorbent and hexane-ethyl acetate (1:1, v/v) as eluting solvent, and from pollen samples by matrix solid-phase dispersion with C18 and acetonitrile, assisted by sonication. The developed methods gave recovery results >90% with relative standard deviationsEste trabajo describe el desarrollo de la metodología analítica para determinar residuos de fipronil en muestras de miel y polen por cromatografía de gases con dos sistemas de detección: espectrometría de masas (GC-MS) y detector de captura de electrones (GC-ECD). El pesticida fipronil se extrajo de las muestras de miel mediante extracción en fase sólida, con alúmina como adsorbente y hexano-acetato de etilo (1:1, v/v) como disolvente de elución, y de las muestras de polen por medio de la dispersión de la matriz en fase sólida, C18, y extracción en baño de ultrasonidos con acetonitrilo. Los métodos desarrollados dieron recuperaciones >90% con desviaciones estándar relativa

Biomonitoring of 21 endocrine disrupting chemicals in human hair samples using ultra-high performance liquid chromatography–tandem mass spectrometry

Rapid industrial growth has increased human exposure to a large variety of chemicals with adverse health effects. These industrial chemicals are usually present in the environment, foods, beverages, clothes and personal care products. Among these compounds, endocrine disrupting chemicals (EDCs) have raised concern over the last years. In the present work, the determination of 21 EDCs in human hair samples is proposed. An analytical method based on the digestion of the samples with a mixture of acetic acid/methanol (20:80, v/v) followed by a solid-liquid microextraction and analysis by ultra-high performance liquid chromatography–tandem mass spectrometry (UHPLC–MS/MS) was developed and validated. The most influential parameters affecting the extraction method were optimized. The method was validated using matrix-matched calibration and recovery assays. Limits of detection ranged from 0.2 to 4 ng g⁻¹, limits of quantification from 0.5 to 12 ng g⁻¹, and inter- and intra-day variability was under 15% in all cases. Recovery rates for spiked samples ranged from 92.1 to 113.8%. The method was applied for the determination of the selected compounds in human hair. Samples were collected weekly from six randomly selected volunteers (three men and three women) over a three-month period. All the analyzed samples tested positive for at least one of the analyzed compounds